1. Field of the Invention
The present invention relates to a cutting machine for cutting a long material such as, for example, a bar material, and to a method for positioning the end of the workpiece to be cut off in that cutting machine.
2. Description of the Prior Art
Various types of cutting machines are used to cut a long material. For example, such a cutting machine may be a band saw machine, a circular saw machine, a disc cutter, or the like.
When such cutting machines are constructed so that the workpiece can be fed automatically to be cut, a main vise device, which is disposed near cutting position and interposedly secures the workpiece during cutting operation, and a feed vise device, which feeds the workpiece, are provided.
Conventionally, to cut the workpiece, first the workpiece is transported to the cutting machine by a suitable transport device, such as a crane, fork lift truck, or the like. Next, after the transported workpiece is clamped in the feed vise device, the feed vise device is moved so that the end of the workpiece is positioned at the cutting position. After the workpiece is interposedly secured in the main vise device, the end section of the workpiece is cut off (the trimming operation). Then, after the end section of the workpiece has been cut off, the feeding operation is performed by the feed vise device from the cut position so that the workpiece is pushed forward by just one unit length (dimension).
Specifically, in such a conventional device, because the end of the workpiece is cut off in the first place, it is easy to set the standard position for the feed vise device or the workpiece wherein the end of the workpiece is positioned in the cutting position; and it is possible to commence feeding the workpiece by a unit length so that semimanufactured goods can be easily cut off.
However, in recent years, along with the advance of multivariety and small number production, or and synchronized production, it has become necessary, for example, to cut only the necessary number of semimanufactured products from one long workpiece and store the remainder of the workpiece in the warehouse. Then, when it again becomes necessary to cut the same workpiece, that workpiece is transported to the cutting machine once more and only the necessary number of semimanufactured products are cut from the workpiece.
When the workpiece is to be cut for the second time, as noted above, because the end of the workpiece was cut during the previous cut it is not necessary to again trim the end of the workpiece. Accordingly, the operator, after transporting the workpiece to tee cutting machine, measures the position of the end face of the workpiece with a scale, and performs an operation for adjusting the end of the workpiece to agree with the cutting position.
The adjustment operation such as outlined above, is carried out by slightly advancing or retracting the feed vise device which has clamped the workpiece. This adjusting operation is not only a lot of work, but because of errors in the scale and the like, a considerable amount of time is required to make the end of the workpiece agree with the cutting position.